Relationship quality in dating couples
From about 1700 a worldwide movement perhaps described as the "empowerment of the individual" took hold, leading towards greater emancipation of women and equality of individuals.
Generally, during much of recorded history of humans in civilization, and into the Middle Ages in Europe, weddings were seen as business arrangements between families, while romance was something that happened outside of marriage discreetly, such as covert meetings.
New types of relationships formed; it was possible for people to live together without marrying and without children.
Information about human sexuality grew, and with it an acceptance of all types of sexual orientations is becoming more common.
Neurobiologist Robert Sapolsky constructed a reproductive spectrum with opposite poles being tournament species, in which males compete fiercely for reproductive privileges with females, and pair bond arrangements, in which a male and female will bond for life.
These species-particular behavior patterns provide a context for aspects of human reproduction, including dating.
However, one particularity of the human species is that pair bonds are often formed without necessarily having the intention of reproduction.